This invention relates to a printing controller and, more particularly, to a controller for controlling a printer capable of changing the resolution.
A type of printer called a page printer has been put to practical use which printer analyzes and records printing information received from a host computer or the like as groups of data items for respective pages to be printed.
This type of printer is designed to print with accuracy and with improved resolution in accordance with printing information on a combination of characters and images formed by image editing using a desktop publishing system recently developed.
A type of printer for printing texts has also been put to practical use, said printer has an internal memory for storing data on character patterns based on different numbers of constituent dots and is capable of printing characters of different sizes on the basis of input control commands.
On the other hand, image scanners having a resolution of, for example, 400 dpi (dots per inch) higher than that of ordinary printers have recently been put to practical use, although the production cost is high.
However, if image data obtained by such a high-resolution image scanner is input into a printer having a lower resolution, it is necessary to thin out the image data so that the image data becomes matched with the resolution determined by text data which is to be used in combination with the image data. The qualities of the printed image are thereby reduced although the original image data is obtained by reading with higher resolution.
Conversely, if an image read by an image scanner having a lower resolution is printed by mixing in text data, the qualities of the whole of the printed page are reduced.
Ordinarily, printing data received from a host computer or the like contains a command which designates the size of characters (text data) to be printed , e.g., 12, 10 or 6 points. For this reason, conventional printers entail another problem in that, in the case of printing of characters having a smaller size, font patterns based on a smaller number of constituent dots are used and the characters are necessarily deformed, resulting in a reduction in the qualities of the print.